simple question.
No matter high cpu ussage, I just need to load one instance for mastering my tracks.

The big problem for getting BIG rms level when mastering with plugins is the limiting process.
ALL the normal limiter plugins make the sound harsh, crisp, too brilliant and looses detail just with a 3 or 4 dbs of GR.
Limiting is the most destructive process of all, and normal plugins will never do a good job.
Could Nebula be someday a good limiter?

are you talking about brickwall limiting? Finall brickwall limiters typically exist on the digital side of the world... There's only a few hardware brickwall limiters that even exist to my knowledge (Pendulum, Waves L2 hardware) it would be nice to get these but I'd settle for a serious library of hardware compressors as is the current trend.

Brickwall limiter I think no, it's mainly a digital approach.
Analog limiter yes. The GMD will be released in the next months, it is the N*****n U473 compressor/limiter from the mastering console which has a good transparent limiter.
Personally I don't use a Brickwall limiter, I prefer to lower the fader manually (automation) if necessary, as B.Katz suggests, but in reality I never reach more than -0.3dB peak at K14.

It's ok when we mix something that need only -14 db rms but when you need to master some dance pop music and need -8 or -7 db rms is a different thing.Most of digital limiters destroys the transients of the sound and made the sound to be poor on dynamic and depth.Most of the time i use clipping on the AD converter to maintain the sound of the mix.I tried all the limiters and i use some of them but even if you put 3 limiters one after the other the sound is not quite right most of the time.Sometimes i need to use a limiter after the clipping to rise the rms with 1 db.Most of the limiters don't sound just right with more than 2-3 db GR.
This situation was made by the rms war witch is stupid by the way.Louder is best for too much people,not personal for me,but this is the present war.
A limiter in Nebula world could be gold but i think is a hard thing to handle -8 rms without distorsions.Time will tell.
Happy mixing to everyone.

Those tracks in the club will NOT sound as good as something that is mixed well at -12 RMS, period, end of story. In fact if you think someone will not buy your music because they have to turn up the volume slider an 8th of an inch on their computer monitor vs. having it sound crushed and lifeless is incorrect as well.

In fact there has been ALOT of market research to disprove a lot of these fallacies on these things. Adding in-harmonic distortion or what people call 'Loudness' does NOT sell records, great music, with a great mix are what do. Else why would people have everything from the Beatles, Bach, to Kraftwerk on their iPod and know how to adjust the volume? Last time I checked sans piracy issues, the more rabid the 'loudness wars' get, the less people buy music. Maybe some connection, but my last album I had it in the contract that the mastering engineer must not go over -14 db RMS (this is a film ambient album). Needless to say there, the label was saying 'its too quiet' compared to the other albums they released. So far its doing much better than all of us thought, and better than the other releases on the label that are 'louder'. So I just stick to writing good music, make the mixes sound as best I can, and make sure the mastering sounds as good as possible. I never worry about rms level when I'm composing, even if its a 4x4 trance anthem.

People react to really good mixed dance music thats mastered for best sound quality, far more than the crushed -7 rms records. Your not adding 'level' in those cases your adding in-harmonic distortion.

You destroy the bass, and the high end is ready hard after prolonged periods of time. At those levels it does not induce any form of aural pleasure, or sound as impressive as you would think even on a bad PA. Its impossible to 'get lost in the music' at that point because your taking out all of the stuff people physically respond to.

So all of this insanity of people worrying more about RMS levels than actual content (as an old German saying goes) 'will all be washed away in a sea of logic'.